Key concepts in Biology

Question 1

Eukaryotic definition

Answer 1

Cells with a nucleus

Question 2

Prokaryotic definition

Answer 2

Cells without a nucleus

Question 3

Name all the parts of a plant cell

Answer 3

Cytoplasm, Chloroplast, Cell wall, Mitochondria, Cell membrane, Ribosomes, Vacuole, Nucleus

Question 4

Name all the parts of an animal cell

Answer 4

Nucleus, Ribosomes, Cytoplasm, Mitochondria, Cell (surface) membrane

Question 5

Name all the parts of a bacterial cell

Answer 5

Chromosomal DNA, Ribosomes, Cell Membrane, Plasmid DNA, Flagellum

Question 6

Specialised cells definition

Answer 6

Specialised cells are cells designed to carry out a particular role in the body

Question 7

Which has a higher resolution light microscopes or electron microscopes

Answer 7

Electron microscopes

Question 8

How do you prepare a microscope slide to look at a specimen e.g. with an onion cell
(there are 4 steps)

Answer 8

1.Take a thin slice of onion
2.Get a clean slide and use a pipette to put a drop of water on it,
3.Use tweezers to put specimen on the slide
4.Carefully lower a cover slip onto specimen and press on it gently to remove air bubbles

Question 9

what is the equation for magnification

Answer 9

magnification=image size divided by real size
(both measurements should use the same units)
triangle = image size on top and magnification multiplied by real size on the bottom

Question 10

What is the definition of an enzyme

Answer 10

Enzymes are proteins that act as biological catalysts - this means they speed up reactions without being used up.

Question 11

What are the substrate and the active site

Answer 11

the substrate is the molecule joining the enzyme
The active site is where the substrate joins

Question 12

What is special about an active sites shape
What happens if the substrate doesn’t match the active site

Answer 12

Enzymes only work with one substrate and the active site is shaped specifically for only that substrate. If a substrate doesn’t match the active site then the reaction won’t be catalysed.

Question 13

What’s another name for the method of the substrate joining the active site

Answer 13

The lock and key method

Question 14

What measurements does Please Never Move Millepedes stand for. And what do you do going from left to right and right to left

Answer 14

Picometres, Nanometers, Micrometers, Millimeters.
Left to right is divide by 1000 right to left is times by 1000

Question 15

Does a bacterial cell have a nucleus?

Answer 15

No

Question 16

What magnification do electron and light microscopes have?

Answer 16

electron = x2,000,000
Light = x1500

Question 17

Organelle defenition

Answer 17

A specialized compartment inside a cell e.g. chloroplast

Question 18

Resolution definition

Answer 18

smallest distance between two points that can be seen as two separate points

Question 19

How many chromosomes does an egg cell and a sperm cell have

Answer 19

23 each

Question 20

total magnification equation

Answer 20

total magnification = magnification on eyepiece lens x objective lens

Question 21

fertilization definition

Answer 21

When the sperm fuses with the egg cell

Question 22

Haploid and diploid cell definitions

Answer 22

Haploid is one set of 23 chromosomes and diploid is 2 sets

Question 23

What are Cilia

Answer 23

Tiny hair like structures on the surface of the cell which contain strands of s substance that can contract and cause wavy movement.

Question 24

Inside the small intestine there are many tiny little folds on the surface of it that are called microvilli what are they for?

Answer 24

These help us absorb our nutrients from the small intestine much quicker.

Question 25

For protein, starch and lipid state the enzyme that breaks them down and what they are broken down into.

Answer 25

Protein - protease - amino acids Starch - amylase - glucose Lipid - lipase - fatty acids

Question 26

What is an enzymes optimum ph definition?

Answer 26

The optimum pH and temperature are the BEST pH or temperature the enzymes work at. It gives the best rate of reaction

Question 27

rate of reaction definition

Answer 27

rate = 1 divided by time

Question 28

What is active transport?

Answer 28

Its where molecules are moved against their concentration gradient from a low to a high concentration. This requires extra energy that is provided by the mitochondria in cells.

Question 29

What is Osmosis?

Answer 29

Osmosis is a type of diffusion that ONLY involves water. The water moves from a higher concentration of water to a lower concentration of water through a partially permeable membrane

Question 30

What are the 6 stages involved in mitosis and which are the 4 that are actually mitosis?

Answer 30

Interphase Prophase Metaphase Anaphase Telophase Cytokinesis

Question 31

What happens in Interphase

Answer 31

This is where the DNA replicates and more organelles are made

Question 32

What happens in Prophase

Answer 32

The nucleus starts to break down. The spindle fibres are made.

Question 33

What happens in Metaphase?

Answer 33

The spindle fibers line the chromosomes up across the middle of the cell (equator)

Question 34

What happens in anaphase?

Answer 34

The spindle fibres contract (shorten) to pull each set of chromosomes to each end (pole) of the cell.

Question 35

What happens in telophase?

Answer 35

The nucleus starts to reform again around each new set of chromosomes

Question 36

What happens in Cytokinesis?

Answer 36

The nucleus starts to reform again around each new set of chromosomes

Question 37

Does meiosis or mitosis create body cells and which other one creates sex cells

Answer 37

Mitosis creates body cells Meiosis creates sex cells

Question 38

What is differentiation?

Answer 38

During growth in animals cells also specialise to gain a specific function. The process of how these cells specialise is called differentiation.

Question 39

Stem cells definition

Answer 39

Cells that divide repeatedly to make many copies of themselves that can differentiate

Question 40

What are the 5 stages of growth to get to a baby?

Answer 40

Fertilization, Zygote, Embryo, Foetus, Baby

Question 41

Why does a red blood cell not have a nucleus and why is the shape of it dipped

Answer 41

To make room for carrying lots of oxygen, and it increases the surface area for gas exchange

Question 42

What is the nervous system made up of

Answer 42

The brain and spinal cord

Question 43

What is the name of this process? The message travels along each neurone as an electrical impulse, between two neurones there is a gap called a synapse, where a chemical called a neurotransmitter is released.

Answer 43

The reflex arc

Question 44

What is the order of the neurons in terms of which is first and then last

Answer 44

Sensory, Relay, Motor (Science Really Matters)

Question 45

What are the reasons for root hair cells having a large surface area?

Answer 45

So they can absorb as much water and minerals as they can from the soil

Question 46

What is the stimulus, receptor cell, sense organ and response in the reflex arc

Answer 46

Stimulus=pain Receptor cell=pain receptor Sense organ= skin Response = pulling hand away by your muscle contracting

Question 47

What's the definition of a stem cell

Answer 47

Cells that divide repeatedly to make many copies of themselves that can differentiate are called stem cells

Question 48

What are Meristem cells

Answer 48

Meristems are regions of unspecialised cells in plants that are capable of cell division

Question 49

What are xylem cells functions?

Answer 49

They transport water and nutrients

Question 50

What are the letters of the two base pairings in DNA

Answer 50

AandT always join together and GandC always join together

Question 51

Gene definition

Answer 51

A gene is a short section of DNA

Question 52

What bonds hold the DNA letter base pairs together

Answer 52

Hydrogen bonds